The present invention relates to a water-soluble keratin hydrolyzate, and more particularly to a water-soluble keratin hydrolyzate suited for use in hair-fixing.
In general, cold waving is conducted by employing a waving lotion for first stage which contains a reducing agent such as thioglycollic acid or cysteine and is adjusted to pH about 9 to about 10 with an alkaline material, and a neutralizing lotion for second stage which contains an oxidizing agent such as sodium bromate or hydrogen peroxide. The waving lotion is applied to the hair to permeate into the hair, and the hair is adequately wound and fixed to rods so as to provide the hair with curl as a result of severance of disulfide linkages by the reducing agent. The neutralizing lotion is then applied to the hair so as to newly form disulfide linkages by the oxidizing agent in the state that the hair is set and to provide the hair with permanent wave.
In this cold waving process, it is necessary to employ an alkaline solution in the first stage to make the hair swell and, therefore, the hair and a head of skin are damaged by an alkaline material. Also, upon the oxidation in the second stage, a side reaction takes place partly to form keratin--S--S--CH.sub.2 COOH linkages, and as a result, the hair is greatly damaged, since, though disulfide linkages are formed again between the keratin molecules, the formation is insufficient.
Such a conventional cold waving process has the disadvantages as stated above, and there is demanded hair fixatives which can produce an excellent waving effect suffering nothing by comparison with a conventional cold waving solution without damaging the hair and skin.